Injection molded article of footwear and method of manufacturing

ABSTRACT

An article of footwear including an upper having an opening for receiving a wearer&#39;s foot, a insole for supporting the wearer&#39;s foot, and an outsole. The upper, the insole and the outsole are comprised of at least two different forms of injection molded polymer materials permanently bonded at interfaces between the different forms of polymer materials to provide an integrally formed and unitary article of footwear. For example, the upper is formed of a limb silicone material, the insole is formed of a silicone gel material, and the outsole is formed of a silicone foam material. The method for manufacturing the integrally formed injection molded article of footwear includes providing a mold having at least one cavity for forming the article of footwear and providing the at least two different forms of polymer materials. A controlled amount of each of said tat lest two different forms of polymer materials are injected into the mold cavity at a predetermined temperature and a predetermined pressure for each of the different forms of polymer materials. The different forms of polymer materials bond to each other at interfaces between the different forms of polymer materials. The polymer materials are cured to provide the integrally formed article of footwear and the article of footwear is removed from the mold.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application takes priority from United States ProvisionalPatent Application Serial No. 60/160,282 filed on Oct. 19, 1999.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to an injection molded shoe and a methodfor producing a unitary footwear formed of two or more siliconematerials using an injection molding apparatus without the need offurther assembly steps.

[0004] 2. Description of the Related Art

[0005] Numerous articles of footwear and methods of manufacturing thefootwear are known in the prior an. Typically, footwear and methods ofmanufacturing footwear consists of assembling numerous parts such as theupper covering, the insole and the outsole and joining these partstogether by stitching, using an adhesive or bonding the parts using aninjection molded polymer.

[0006] The simplest of these methods of construction include stitchingtogether overlapping layers of leather or cloth to form an uppercovering for the foot and then using an adhesive to attach a preformedoutsole. Other construction methods include forming an injection moldedoutsole and/or insole and integrally joining the upper during themolding process of the sole unit such as, for example, joining an upperand a preformed rubber outsole with a foamed poly-urethane, injectionmolded insole.

[0007] Although articles of footwear have been manufactured whereinportions of the footwear are formed by injection molding polymers, theprior methods still have required the preforming of certain portions ofthe shoe and joining the portions together using adhesives or otherpolymers which present other disadvantages such as the adhesive orjoining materials passing into other portions of the shoe and providingan complex and lengthy manufacturing and assembling process.

SUMMARY OF THE INVENTION

[0008] It is an object of this invention to provide an injection moldedintegrally formed article of footwear shoe which does not require theassembling and joining of numerous parts. The article of footwearaccording to the present invention includes an upper having an openingfor receiving a wearer's foot, a insole for supporting the wearer'sfoot, and an outsole. The upper, the insole and the outsole arecomprised of at least two different forms of injection molded polymermaterials permanently bonded at interfaces between the different formsof polymer materials to provide an integrally formed and unitary articleof footwear. The article of footwear preferably includes a plurality ofinjection molded points on the bottom of the outsole. The at least twodifferent forms of polymer materials are, preferably, different forms ofsilicone such as for example, a limb silicone material and silicone foamand gel material. For example, the upper is formed of a limb siliconematerial, the insole is formed of a silicone gel material, and theoutsole is formed of a silicone foam material.

[0009] A method for manufacturing the integrally formed injection moldedarticle of footwear according to the present invention includesproviding a mold having at least one cavity for forming the article offootwear and providing the at least two different forms of polymermaterials. A controlled amount of each of said at least two differentforms of polymer materials are injected into the mold cavity at apredetermined temperature and a predetermined pressure for each of thedifferent forms of polymer materials. The different forms of polymermaterials bond to each other at interfaces between the different formsof polymer materials. The polymer materials are cured to provide theintegrally formed article of footwear and the article of footwear isremoved from the mold.

[0010] The step of injecting into the mold cavity a controlled amount ofeach of the polymer materials, further includes, for example, couplingat least one distributor valve to a supply of each of the differentforms of polymer materials and coupling a plurality of sprues to themold leading to the mold cavity and to the distributor valves Each ofthe different forms of polymer materials are distributed in thecontrolled amounts from the distributor valves and are injected into themold cavity through the plurality of sprues.

[0011] A control device including a microprocessor is connected, forexample, to each distributor valve and to each of the supplies of thedifferent forms of polymer materials for controlling the distribution ofthe polymer materials. The temperature and pressure of the supplies ofthe different forms of polymer materials are also controlled.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention may be better understood, and its numerousobjects, features, and advantages made apparent to those skilled in theart by referencing the accompanying drawings.

[0013]FIG. 1 is a side elevational view of an article of footwearaccording to a first embodiment of the present invention;

[0014]FIG. 2 is a cross-sectional view of the article of footwear takengenerally along line 2-2 of FIG. 1;

[0015]FIG. 3 is a side elevational view of an article of footwearaccording to a second embodiment of the present invention;

[0016]FIG. 4 is a cross-sectional view of the article of footwear takengenerally along line 4-4 of FIG. 3;

[0017]FIG. 5 is a bottom elevational view of the article of footwearaccording to the resent invention, and

[0018]FIG. 6 is a schematic diagram illustrating the manufacture of theshoe article according to the present invention.

DETAILED DESCRIPTION Of THE PREFERRED EMBODIMENTS

[0019] The following sets forth a detailed description of thebest-contemplated mode and embodiments for carrying out the invention.The description is intended to be illustrative of the invention andshould not be taken to be limiting.

[0020] Referring to FIGS. 1-5, the article of footwear or shoe 10according to the present invention includes a first portion or upper 12,a second portion or insole 14, and a third portion or outsole 16. Asdiscussed below in greater detail, the entire shoe 10 is manufacturedusing different forms of polymers without the need for preforming,assembling and joining separate pants of the shoe. The upper 12 includesan opening 28 for receiving a wearer's foot and the insole 14 supportsthe wearer's foot. The upper 12, the insole 14 and the outsole 16 arecomprised of at least two different forms of injection molded polymermaterials permanently bonded at interfaces between the different formsof polymer materials to provide an integrally formed and unitary shoe10.

[0021] For example, the upper 12, the insole 14, and the, outsole 16 areinjection molded into an integrally formed shoe 10 using at least twodifferent types or forms of polymers in a single mold wherein thedifferent forms of polymers used for the different portions of the shoe10 mesh at interfaces 18 and permanently bond the upper 12, the insole14, and the outsole 16 of the shoe 10 together providing an integrallyformed article of footwear.

[0022] The method of manufacturing the integrally formed injectionmolded article of footwear according to the present invention isillustrated in FIG. 6. As shown the shoe 30 is manufactured in mold 32having a mold cavity 34. At least two different forms of polymermaterials, preferably, different forms of silicone such as, for example,silicone foams and silicone gels, are provided in extruders 36, 38 and40. Nozzles or sprues 42, 44 and 46 are connected to extruders 36, 38and 40 and lead into the mold cavity 34 for providing the differentpolymer materials such that the polymer materials are injected into themold cavity 34 in a viscous condition. Distributor valves 48, 50 and 52are positioned in conduits leading from the outputs of the extruders 36,38 and 40 to sprues 42, 44 and 46 for distributing the viscous polymermaterials into the mold cavity 34 in pre-selected and controlledamounts.

[0023] Extruders 36, 38 and 40 are driven by motors 54, 56 and 58. Theoperation of the motor 54, 56 and 59 is controlled by control device 60which includes, for example, timers, adjustment devices and 2.microprocessor included, for example, with input terminal 62. Thecontrol device 60 including the input terminal 62 allow the motors 54,56 and 52 to be programmed such that the motors 54, 56 and 58 areactuated for a selected, predetermined length of time or at a selected,predetermined pressure for each of the extruders 36, 38 and 40. Thedistributor valves 48, 50 and 52 are also connected to the controldevice 60. Correspondingly, the distributor valves 48, 50 and 52 providethe different forms of polymer materials at predetermined time intervalsand at predetermined portions of the mold cavity 34 causing the shoe 30portions to be formed in the mold cavity 34.

[0024] The shoe 30 portions mesh at the interfaces 18 between adjacentportions (see FIGS. 2 and 4) and permanently bond to each other toprovide a single part or unitary shoe 30. The polymer materials arecured providing a single part. integrally formed shoe 30 which requiresno additional manufacturing steps such as assembling or joining separateportions of a shoe. After curing, the shoe 30 is removed from the moldcavity 34. The curing time varies depending on the selection and type ofpolymer materials. Although a preferred method of manufacturing theintegrally formed injected molded shoe of the present invention isillustrated in FIG. 6, other known processes used for injection moldingpolymer materials can be incorporated in to the manufacturing methodillustrated.

[0025] A number of variations the injection molded shoe are conceivable,such as, for example, the shoe 10 can be manufactured having a varietyof closure elements such as, for example, the lace loops 22 illustratedin FIG. 1 or the shoe can be simply pulled onto the foot such as the“bootie” illustrated in FIG. 3 The shoe 10 can be manufactured andmolded including any type of decorative ornamentation formed within themolded shoe or any three-dimensional (3D) design such as the 3D design26 illustrated in FIG. 3 The shoe 10 can also be manufactured and moldedincluding other molded parts such as, for example, heel pull straps andsimilar external additions, as well as including reinforcements and/orstiffeners embedded into the molded shoe 10 such a the ornamentalelement 66 and the functional element 68 for insole support illustratedin FIG. 2.

[0026] Referring to FIGS. 1-4, the article of footwear or shoe 10 of thepresent invention is manufactured, preferably, entirely of siliconeusing different forms of silicone such as, for example, a silicone foamfor the outsole 16, and a silicone gel for the insole 14, and limbsilicone for the top and sides or upper 12. The different forms of thesilicone then work together in a synergetic manner to dissipate energyfrom the bottom up through the sides of the shoe 10 emulating, forexample, an animals paw in energy absorption and dissipationparticularly advantageous in the field of athletic shoes or sneakers.The use of the different forms of silicone also provides other advantageincluding permanently bonding between the different forms of siliconeprovide a single part or unitary shoe 10. Another advantage provided bythe injection molded shoe 10 according to the present invention is thatthe silicone provides a shoe that is approximately 75% breathable whichaids in dissipating heat also particularly useful in athletic shoes.

[0027] As illustrated in FIGS. 2 and 4 and particularly shown in FIG. 5,the bottom 20 of the shoe 10 preferably includes silicone gel “points”24 which provide improved energy dissipation and improved traction. Inthe manufacture of the shoe 10. numerous injection sites and sprues (seeFIG. 6) can be used on the mold 32 to allow for the silicone gel points24 to be formed from the silicone gel insole 14 portion (as shown inFIG. 2) or the silicone gel points 24 can be individually injected (asshown in FIG. 4).

[0028] It should be noted that the present invention may be usefullyapplied not only to athletic shoes, particularly noted by way of examplebut to all types of shoe and boot designs. A variety of colors andthree-dimensional designs as well as various embedded elements, bothfunctional and ornamental, can be easily applied to the article offootwear cording to the present invention.

[0029] While preferred embodiments have been shown and described,various modifications and substitutions may be made thereto withoutdeparting from the spirit and scope of the invention. Accordingly it isto be understood that the present invention has been described by way ofillustrations and not limitations.

What is claimed is:
 1. A method for manufacturing an integrally formedinjection molded article of footwear, comprising: providing a moldhaving at least one cavity for forming the article of footwear;providing at least two different forms of polymer materials; andinjecting into the mold cavity a controlled amount of each of said atleast two different forms of polymer materials at a predeterminedtemperature and a predetermined pressure for each of the different formsof polymer materials; bonding each of the different forms of polymermaterials to the other at an interface between the different forms ofpolymer materials; curing said different forms of polymer materials toprovide the integrally formed article of footwear; and removing thearticle of footwear from the mold.
 2. A method, as recited in claim 1,wherein the step of injecting into the mold cavity a controlled amountof each of said at least two different forms of polymer materials,further comprises coupling at least one distributor valve to a supply ofeach of said at least two different forms of polymer materials; couplinga plurality of sprues to the mold leading to the mold cavity and to thedistributor valves wherein each of said at least two different forms ofpolymer materials arc distributed in said controlled amounts from thedistributor valves and are injected into the mold cavity through theplurality of sprues.
 3. A method, as recited in claim 2, furthercomprising: connecting a control device including microprocessor to eachdistributor valve and to each of said supply of the at least twodifferent forms of polymer materials wherein the control device controlsthe distribution of said at least two different forms of polymermaterials; and controlling the temperature and pressure of said supplyof the at least two different forms of polymer materials.
 4. A method,as recited in claim 3, wherein the control devise controls thetemperature and pressure of said supply of the at least two differentforms of polymer materials.
 5. A method, as recited in claim 1, whereinthe at least two different forms of polymer materials are differentforms of silicone.
 6. A method, as recited in claim 1, furthercomprising: embedding a functional element into the article of footwear.7. A method, as recited in claim 1, further comprising: embedding anornamental element into the article of footwear.
 8. Ar article offootwear comprising: an upper having an opening for receiving a wearer'sfoot; a insole for supporting the wearer's foot: and an outsole; andwherein the upper, the insole and the outsole are comprised of at leasttwo different forms of injection molded polymer materials permanentlybonded at interfaces between said different forms of polymer materialsto provide an integrally formed and unitary article of footwear havingsaid upper, said insole and said outsole.
 9. An article of footwear, asrecited in claim 8, further comprising: a plurality of injection moldedpoints on a bottom of said outsole.
 10. An article of footwear, asrecited in claim 8, further comprising: an injection moldedthree-dimensional ornamental design.
 11. An article of footwear, asrecited in claim 8, wherein the at least two different forms of polymermaterials are different forms of silicone.
 12. An article of footwear,as recited in claim 8, wherein said upper is formed of a limb siliconematerial.
 13. An article of footwear. as recited in claim 8, whereinsaid insole is formed of a silicone gel material.
 14. An article offootwear, as recited in claim 8, wherein said outsole is formed of asilicone foam material.
 15. An article of footwear, as recited in claim9, wherein the injection molded points are formed of a silicone gelmaterial.
 16. An article of footwear, as recited in claim 8, furthercomprising: an embedded functional element.
 17. An article of footwear,as recited in claim 8, further comprising: an embedded ornamentalelement.